Electrical plug-switch.



E. J. 'OVINGTON.

ELECTRICAL PLUG SWITCH.

APPLICATION FILED NOV.29. 1913.

Patented Mar. 27, 1917.

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APPLICATION FILED NOV.29' I913- Patented Mar. 27, 1917.

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EDWARD J'. OVINGTON, OF NEVITON CENTER, MASSACHUSETTS, ASSIGNOR TO SIMPLEX ELECTRIC HEATING COMPANY, OLE CAMBRIDGE, MASSACHUSETTS, A CORPGRATION OF MASSACHUSETTS.

ELECTRICAL PLUG-S'WITCH.

Application filed November 29, 1912-.

To all whom it may concern:

Be it known that I, EDWARD J. OVINGTON, a citizen of the United States, and resident of Newton Center, county of Middlesex, State of Massachusetts, have invented an Improvement in Electrical Plug-Switches, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My present invention relates to electrical plug switches and its object is to improve and perfect a connector switch for electrical use, and to provide a plug switch wherein the plug contact members are themselves relatively movable to accomplish a switch effect. My improved plug switch may be utilized and employed as an ordinary multiposition plug being withdrawn from and reapplied to an ordinary plug socket, but preferably I employ a novel form of plug, whereby the cooperating contact members for the plug and socket may be relatively moved into different combinations, thus constituting a. switch. Heretofore plug switches have simply involved the combination of plug members, together with separate switch mechanism connected to one of said mem bers, usually the plug, but my intention contemplates the provision of a plug switch without any additional switch mechanism, but which is so constructed and arranged as to constitute itself the switch, as well as the plug, which connects the current transmitting members under tension. The plug switch of my present invention may be ad vantageously employed in a large variety of ways and uses, being especially adaptable as a connector switch to be utilized either as a plug to be separated and reconnected in or out of circuit, or in different circuits, or to be partially turned as a switch, to either turn current on or off, or into circuit for different amounts of current. My improved plug switch therefore may be used as an ordinary connector plug, in case it is not desired to utilize the switching feature, as when the switch portions become damaged, or stick in action, or the like. Also it can be used Specification of Letters Patent.

Patented Mar. 27, 191'7.

Serial No. 803,709.

to switch on or elf the current as an ordiary electrical switch, or as a two or three heat switch to supply maximum, medium, and minimum current for electrical heaters, coils, boilers, and the like.

A. further important feature of the present invention is the provision of automatic 'means to hold the receptacle and plug in as- 'feature of this invention is that I provide means to localize the arcing on the contact members, so that, when the plug is utilized as a switch and turned from one position to another, the entire plug member will be prevented from being worn, roughened 0r pitted by the current arcing at divers points during successive switching movements, but will be confined or localized to a single portion of the plug member, so that substantially the entire length of the plug member will be maintained perfectly smooth and insure the smooth wearing both of itself and its cooperating brush or contact, and prevent roughening of either. This feature is of particular importance, especially where a smooth contacting surface between a copper brush and steel plug member is desired, as in the preferred form of my present invention.

In the preferred forms of my invention as herein illustrated, I have shown my improved plug switch in a simple form, capable of being employed to turn current on or off, as well as being capable of use as a plug to be removed and refitted to its cooperating socket member to turn current on or off; also as a three-heat plug switch, supplying three selective degrees of heat, wherein equal or unequal amounts of electrical resistance are utilized. I also illustrate an improved means to retain and release the plug and receptacle members.

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Other features of the invention, details of construction, and novel combinations of parts will be more fully illustrated and claimed hereinafter.

Referring to the drawings, showing preferred embodiments of my improved plug and connector switch,

Figure 1 is a view of the socket and plug members in operative position;

Fig. 2 being a bottom plan view of the socket removed from the plug member;

Fig. 3 is a plan view of the three-plug member;

Fig. i is a view line l l of Fig. 2;

Fig. 5 is a view in cross section on the line 55 of Fig. 2, with the plug member also in cross section shown in position;

Fig. 6 is a view of the receptacle and plug members united with the front casing of the receptacle member removed;

Fig. 7 is an enlarged detail view, partly in cross section of the means for holding and releasing the central plug member from the central socket of the receptacle member;

Figs. 8, 9, and 10 are plan views of the different relative positions of the plug and socket members;

Figs. 11, 12 and 13 being corresponding in cross section on the diagrammatic views respectively of the same positions as shown in Figs. 8, 9, and 10 illustrating my invention in a three-heat plug switch, wherein two electrical heaters of equal winding or heating power are employed;

Figs. 14:, 15, and 16, together with Figs. 17 18, and 19, are respective plan and diagrammatic views of a three-heat plug switch, wherein unequal electrical heaters are utilized;

Figs. 20, 21, 22, and 23 are plan and respectively corresponding diagrammatic views of my plug switch as a simple switch to turn current on or off and Figs. 24, 25, 26, and 27 are plan and respectively corresponding diagrammatic views illustrating my plug switch as a simple switch, but providing two degrees of heating supply current.

In the drawings I have shown in conven': tional form several modifications of a connector switch or plug switch comprising two members, one carrying the three plugs and the other member having cooperating sockets and switch members, which sockets are in the form of spring members and comprise the automatic means to maintain the plug members under tension in contact therewith and also to automatically throw the plug members into or out of full current receiving position. Either the plug member or the socket member may be fixed rigidly while .the other is free to turn, or both members may be at the end of a length of wire and each free to receive a rotative movement or to be connected from and reconnected to the other member. In. the draw ings Figs. 1 to 10, 1 represents the member carrying a central plug stem 2 and a co6perating pair of plugs 23 and f at substantially equal distances therefrom, which members 2, 8, and 4 are formed preferably of hardened steel. These stems may be secured to the member carrying them in any suitable manner, being herein illustrated as secured by collars 5 and nut 6 (see Fig. to which the wires leading therefrom may also be secured in any conventional manner (not shown).

The socket member comprises a casing 7, and a core 8 which core carries a central metallic bushing 9 fitted in a socket bored therefor, adapted to receive the central plug stem 2, and a metallic brush 10, arranged in a recess provided therefor at one side of the core 8, which brush is in electrical connection with the inner bushing 9 by a metallic bolt 11. The supply wires 12 and 13 for the socket member are led through a central recess lt in the casing 7, and the side passage 15, the wire 12 being led to the side brush 10 and secured by the head of the bolt 11 as a binding post. The wire 13 is led to a binding post 16, which post also holds to the core 8 a central contact member, preferably comprising two members 17 and 18, both constituting a terminal for the wire 13. This central bushing I make of two members and have the contacting portions of each member arranged for separate and individual yielding action by splitting the same. Thus that portion of the brush 18 which will be in contact with the plugs 2 and 3 during the operation of the device is formed into brush portions 19 and 20, and the corresponding contact portions of the inner brush 17 are similarly divided (see Fig. 2) into separately yielding sections 21 and 22. The recess 28 in the core 8 carrying the central brush is suflicient in depth and extent to provide a substantial yield for all of these brush members. Each end portion of the inner brush members 21 and 22 is ribbed, as indicated at 2d and 25, so that as the plug members 2 and 3 are forced into engagement therewith as will be described, a substantial springing action will be imparted to both inner and outer brush members. This construction aids in automatically throwing the stem and brush members into full electrical contact or out of it and maintains said contact under a full and sufficient tension to insure said contact throughout the entire length of the stem and brush members.

The switch member has its core 8 formed with a peripheral recess 26 entirely around the bottom surface thereof and within the casing 7, (see Fig. 3) so as to permit the plug members 3 and I to traverse said recess as during the relative rotative movement of the socket member to the plug member. The two members may be connected as an ordinary plug switch, the central stem 2 01 one member fitting in the central bushing 9 of the socket member and the two plug stems 3 and a being joinedto the bushings or contacts and 17 and 18 in different positions to switch the current in the different circuits desired.

InFigs. 8, 9, and 10, and their corresponding diagrammatic views Figs. 11, 12 and 13, I have illustrated the different switching positions in which current may be turned. It will be understood that the stems 2, 3, and 4 will be in connection with the coils of resistance 27 and 28 through the wire 29, as shown in Figs. 11, 12, and 13. The supply current from a suitable source of supply being in connection with the binding posts 11 and 16, and consequently with the brushes 10 and 18 respectively; the contact ailorded by the post 16 including not only le brush 18, but 17 also as a part of this terminal. In the position shown in Figs. 8 and 11, the resistance coils 27 and 28 are in series, and a low heat results; in the position shown in Figs. 9 and 12 the resistance coil 27 is in action, the coil 28 being substantially short circuited by the current passing through the plug 3 and wire 29 and a medium heat results; in the position shown in Figs. 10 and 13 the resistance coils 27 and 28 produce a divided current, being in multiple, and a high heat results. t will be understood that the resistance coils 27 and 28 connected with the stems 2, 3, and 4, will be a part of the heater, stove, or the like slightly modified form, wherein resistance coils of unequal winding or resistance may be employed, the coil designated by 30 being of coarse or heavy wire and of low resistance, the coil 31 being of fine wire and high resistance. The switching of the current is eifected in the same manner, Figs. 1% and 17 being plan and diagrammatic views of the same position affording low heat; Figs. and 18 ofa second position aliording high heat; and Figs. 16 and 19 of a third position affording medium heat.

In Figs. 20 to 23 I have illustrated a simple form of my invention employed as a switch merely, utilizing a single coil of resistance 32 to turn current on or off. In this form the stem 3 is useless and inoperative excepting as a guide to insure the satisfactory operation of the switch members, to hold the same under tension in the several positionsand to assist in the completion of the throw of the switch into or out of full contact.

Figs. 24 to 27 show a simple switch mechanism to atlord two different heats employing resistance coils 33 and 31- of equal amount operated in the same manner as already described.

I have discovered that in operating a switch, such as herein illustrated, wherein contacts 10 and 18 are utilized on one member, and stems 3 and 1 on the other, that a considerable arcing is apt to result in switching the members from one position to another. This arcing is so intense as to reughen or pit the contact members both 10 and 18 and the stems 3 and 41, so as to interrupt the surfaces thereof and prevent a smooth electrical contact throughout the length and extent of the members. In order to obviate this difiiculty, I have discovered that the arcing may be localized and confined to a single point, thus preserving the entire remaining surfaces of the stems 3 and 4: in the contact members 10 and 18, thereby restricting the roughcning and pitting iully, because restricting the arcing, to the single point. I accomplish this result by providing'the forward portions of the contact pieces 10 and 18 with slight projections 35, 35, (see Fig. 6). These projections come into Contact first with the stems 3 and a as they are switched into position and thus confine the arcing to the points on the stems which the projecting portions 35 first touch. This leaves practically the entire length of both members smooth and insures an etficient electrical contact. This feature is of special importance in switching devices of this general type.

In Figs. 11 to 16, and 24 and 25, I have illustrated a slightly modified form of the inner beveled brush member, wherein a single point 36 is employed on either side of which the stems 2 or 3 will be held in spring tension as previously explained with regard to the spring ribbed points 21 and 25 in the form shown in Fig. 2.

The central socket member 9 is preferably formed of a plurality of sections, as clearly illustrated in Figs. 8, 9, and 10, these sections having a spring action permitted by the plurality of openings 37 between the same and the diameter of the socket in which the member 9 is fitted, which is slightly greater than the exterior diameter of the metallic contact 9. The innermost part of the member 9 is threaded at 38 to receive the correspondingly threaded end of the bolt 11, which, as already explained, provides an electrical connection from the wire 12 and brush 10 to the central member 9. In order to maintain the two plug members in assembled position, I prefer to groove the end portion of the center stem 2, as shown at 39 in Fig. 5, and arrange a pin 40, secured to a ring 41 fitting within a bored recess 42 in the core 8, transversely to the socket for the contact 9, which ring 41 is normally pressed outwardly by a coiled spring 43 seated in the bottom of the recess, see Fig. 7 and adapted to be released by inward movement through a projecting button l4 to free the pin 4L0 from engagement with the recess 39, in the stem 2 as will be readily understood.

The operation of my novel connector switch has already been described, and it will be appreciated that the plug and socket members thereof may be interchanged so that one is the movable portion and the other the fixed member, that both may be at the end of a wire, or that either may be aflixed permanently in any desired position, as part of an electrical stove for example. Also that the difierent circuits in which the current may be switched may be utilized either by a partial relative rotative movement of the plug and socket members, or by entirely disconnecting one member from the other and reconnecting it in the different switched relation after the manner of an ordinary plug. The rotative movement however, is that preferred, and in such case the feature whereby the arcing is localized and the electrical contacts of each member are maintained smooth, insuring an efiicient electrical contact, is eflective. Also the spring tension of the ribbed portions 24 and 2-5, or 86, is eflective to complete the throw of the switch mechanism into one circuit or out of one circuit and into another, as already explained.

To facilitate the switching operation, and as a guide to the positions in which the two members may be turned, as for instance, first, second, and third heat for example, I have marked the exterior of the portion 7 with guide lines (see Fig. 1), which, when registering with the horizontal guide line as on the member 2 (as shown in Fig. 3), will show the particular current turned on through the switch. These guide lines also aid the operator in determining the full switching position in which the two members may be turned, although as previously explained, this full switching position will be automatically effected by the construction shown.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A connector switch, having two members constructed for relative rotation independent of longitudinal movement, comprising combined connector and switch members having provision to hold the current transmitting members centered together under tension, and means actuated by a relative rotative movement only between said switch members to effect changed current conditions from one member to the other, one of said members constituting a pivot for said relative rotative movement.

2. A connector switch, having two members constructed for relative rotation independent of longitudinal movement, comprising combined connector and switch members, one of said members constituting the pivot for rotation, yielding means on one switch member to impel the cooperative member to full centered contact position, and means actuated by a partial rotative movement only between said switch members to efiect changed current conditions from one member to the other.

3. A connector switch, having two members constructed for relative rotation independent of longitudinal movement, comprising combined connector and switch members having provision to change current transmission from one member to another by relative rotative movement only between the switch members, one of said members constituting the pivot for said rotative movement, and means to automatically impel the cooperating connecting' members into center current contact position.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

EDWARD J. OVINGTON.

Witnesses:

ALBERT E. DAVIDSON, BETHUEL G. ADAMS.

copies ot this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, 1 0. 

